feat: bot.myStatus - to simplify my_chat_member

src/composer.ts

@@ -78,6 +78,28 @@ interface CommandContextExtn {
  args: string[]
 }
 
+interface StatusContextExtn {
+ /** Shorthand for old and new my_chat_member status */
+ status: {
+ /** */
+ change: StatusChange
+ /** Shorthand for update.my_chat_member.old_chat_member.status */
+ prev: tg.ChatMember['status']
+ /** Shorthand for update.my_chat_member.new_chat_member.status */
+ current: tg.ChatMember['status']
+ }
+}
+
+type StatusChange =
+ | 'blocked'
+ | 'unblocked'
+ | 'joined'
+ | 'left'
+ | 'banned'
+ | 'restricted'
+ | 'promoted'
+ | 'demoted'
+
 const anoop = always(Promise.resolve())
 
 export class Composer<C extends Context> implements MiddlewareObj<C> {
@@ -161,7 +183,7 @@ export class Composer<C extends Context> implements MiddlewareObj<C> {
  Middleware<NarrowedContext<C, tt.MountMap['text']> & CommandContextExtn>
  >
  ) {
- return this.use(Composer.command<C>(command, ...fns))
+ return this.use(Composer.command(command, ...fns))
  }
 
  /**
@@ -297,6 +319,23 @@ export class Composer<C extends Context> implements MiddlewareObj<C> {
  return this.command('settings', ...fns)
  }
 
+ /**
+ * Listen for the bot's status change in chats
+ *
+ * * `joined`, `left`, `promoted`, `demoted`, `banned`, `restricted` will only be triggered in non-private chats
+ * * `blocked`, `unblocked` will only be triggered in private chats
+ */
+ myStatus(
+ change: MaybeArray<StatusChange>,
+ ...fns: NonemptyReadonlyArray<
+ Middleware<
+ NarrowedContext<C, tt.MountMap['my_chat_member']> & StatusContextExtn
+ >
+ >
+ ) {
+ return this.use(Composer.myStatus(change, Composer.compose(fns)))
+ }
+
  middleware() {
  return this.handler
  }
@@ -917,6 +956,35 @@ export class Composer<C extends Context> implements MiddlewareObj<C> {
  }
  }
  }
+
+ static myStatus<C extends Context>(
+ type: MaybeArray<StatusChange>,
+ ...fns: NonemptyReadonlyArray<
+ Middleware<
+ NarrowedContext<C, tt.MountMap['my_chat_member']> & StatusContextExtn
+ >
+ >
+ ): MiddlewareFn<C> {
+ const changes = Array.isArray(type) ? type : [type]
+ const handler = Composer.compose(fns)
+
+ return Composer.on('my_chat_member', async (ctx, next) => {
+ const status = {
+ prev: ctx.myChatMember.new_chat_member.status,
+ current: ctx.myChatMember.old_chat_member.status,
+ }
+
+ for (const change of changes) {
+ // todo: decide whether to normalise and fire for all matching changes, or just the first matching one
+ // ref: https://github.com/telegraf/telegraf/issues/1872
+ if (checkStatusChange(change, ctx.chat.type, status))
+ return handler(
+ Object.assign(ctx, { status: Object.assign(status, { change }) }),
+ next
+ )
+ }
+ })
+ }
 }
 
 function escapeRegExp(s: string) {
@@ -950,6 +1018,7 @@ function getEntities(msg: tg.Message | undefined): tg.MessageEntity[] {
  if ('entities' in msg) return msg.entities ?? []
  return []
 }
+
 function getText(
  msg: tg.Message | tg.CallbackQuery | undefined
 ): string | undefined {
@@ -969,4 +1038,23 @@ function normaliseTextArguments(argument: MaybeArray<string>, prefix = '') {
  .map((arg) => prefix && typeof arg === 'string' && !arg.startsWith(prefix) ? `${prefix}${arg}` : arg)
 }
 
+function checkStatusChange(
+ change: StatusChange,
+ chatType: tg.Chat['type'],
+ status: Record<'prev' | 'current', tg.ChatMember['status']>
+) {
+ const { prev, current } = status
+ if (chatType === 'private') {
+ if (change === 'blocked') return current === 'kicked'
+ if (change === 'unblocked') return current === 'member'
+ } else {
+ if (change === 'joined') return prev === 'left' || prev === 'kicked'
+ if (change === 'banned') return current === 'kicked'
+ if (change === 'left') return current === 'left'
+ if (change === 'restricted') return current === 'restricted'
+ if (change === 'promoted') return current === 'administrator'
+ if (change === 'demoted') return prev === 'administrator'
+ }
+}
+
 export default Composer